Apparatus for controlling the level of liquids



y 1933- H. H. MARSHALL 1,917,045

APPARATUS FOR CONTROLLING LEVEL LIQUIDS Filed May 8, 1950 Y ATTORN EYPatented July 4, 1933 UNlTED- STATES PATENT a was HENRY n. MARsHALL, orHIGHLAND PARK, NEW JERSEY,'ASSIG1\IOR, BY, MEsRE As- SIGNMENTS, T0cARRIER RESEARCH coRroRA'rIoN, 0F NEWARK, NEW JERs Y, A

v CORPORATION OF JERSEY APPARATUS FOR CONTROLLING THE LEVEL OF LIQUIDSApplication filed. May 8,

compression .type and will be described asap plied to such a system. i

The condensed refrigerant in liquid form is collected'inhighpressure'receptacles or containers, such as condensers, in the highpressure side of such compression systems, and for uniform and efficientoperation the liquid level in such containers should be maintainedsubstantially the sameduring operation. Heretofore, it has been proposedto control the liquid level by using float valves. For example, thereare systems in each of which the refrigerant (which may consist of anysuitable material, such as ammonia, sulphur dioxide, methyl chloride orcarbon di oxide) is condensed to liquid form in a condenser, and drainedimmediately into a small -float valve trap, liquid refrigerant beingdischarged from said trap into the low pressure side of the system eachtime the liquid in the trap rises to a'predetermined level.

The float valve controls have, however, giv- "en considerable troubleand they are subject to various disadvantages. For example, the valve ineach of such systems must be located adjacent to or immediately belowthe condenser or receptacle and. must be connected with one or morecooling devices or refrigerators by one or more low pressure, lowtemperature lines which must be thermally insulated, as by use of cork.

The general object of the present invention is to provide an improvedliquid level control.

A further object is to provide an improved liquid level control for highpressure containers or receptacles. Another object is to providethermostatic liquid control means for this purpose.

The aforesaid and other objects are at- 1930. semu No. 450,653.

tained by apparatus of which a preferred embodiment is illustrated inthe accompanying drawing, which: Fig. 1 is a fragmentary elevation of arefrigerating systemembodying one form of the invention, parts being.

broken away to show the underlying structure; and F ig. 2 is a centralvertical section of the expansion valve.

Referring to the drawing, the hot vdischarge gas from a compressor (notshown) is conducted through a ipe or conduit 10 to. one end of a tube ortube section 11 arranged horizontally at the side of a receptacle orcondenser 12, which may be of shell and tube construction, and saiddischarge gas is conducted from the other end of said tube section 11through a pipe 13 to the top of the condenser 12. From the bottom of thecondenser, liquid collected in the condenser passes through a pipe 14 tothe high pressure side of a suitable expansion or pressure reducingvalve 15, and enters a chamber 16 closed at its upper side by adiaphragm ll. The liquid refrigerant at condenser pressure acts on thelower side of the diaphragm 17 and tends to flex it upwardly and therebypermit a valve member 18 to be lifted, by suitable means including aspring 19, out of engagement with a valve seat 20 forming the bottom ofthe chamber 16 in the. valve body. Upon such lifting of the valve orvalve member 18, a port 21 in the valve seat 20 will be opened thuspermitting the compressed refrigerant to pass downwardly through theport and to the outlet 22 at the low pressure side of the expansionvalve 15.

At the upper side of the diaphragm 17 is a chamber 23 enclosed -betweenthe diaber 28 surrounding the horizontal tube sec-- tion 11 andsurrounded in turn by a chamber bottom thereof. At its top andpreferably "near its other end the jacket is connected by a pipe 3011with the condenser 12 at a point above the liquid level in saidcondenser. For the purpose of providing a suitable charge of elasticfluid in thermal chamber 28, line 26 and chamber 23 of the valve, thepipe or line 26 may be connected with the high pressure line or pipe 14through a pipe 31 containing a valve 32. In charging this part of thesystem, the valve 32 is opened so as to produce the desired pressure andwhen the desired pressure is indicated on a gauge 33 connected with thepipe 26, the valve is closed. 1

'The thermostatic valve 15 is of simple form as here disclosed. In orderthat the valve may be tightly closed, the main body of the movable valvemember 18 is tapered to fit closely against the correspondingly taperedupper end of the port 21. For guidance and operation, the valve member18 may be provided at its upper end with a reduced extension which fitsinto an opening or recess at the lower side of a diaphragm pusher 34which is suitably guided *in the upper part of the valve body and isprovided at one point of its periphery with a recess or opening 35 toassure communication between the chamber 16 and the lower surface of thediaphragm 17. I

" The valve member 18 is also provided at its lower end with a reducedextension which fits into an opening in the upper end of alongitudinally movable member 36 engaged at its lower end by the spring19. The member 36 is slidably mounted in a plug 37 screwed into thelower side of the valve body and the spring 19 is housed in a tubularextension of said plug. To avoid interference with the operation of themember 36 communication between the interior of the valve and theinterior of the tubular extension of p the plug 37 may be effected inany suitable manner, as by providing a groove 37 a in member 37. At itslower end the spring is engaged by a spring cap/38 located on the upperend of a screw or spindle 39 having a threaded upper end screwed into aplug 40 which in turn is screwed into the lower end of thespring-containing tubular portion of "the plug 37. Leakage around thespindle may be prevented by use of packing 41 in a suitable opening inthe lower end the plug 40, the packing being engaged by a packing gland42 forced inwardly against the packing by means of a cap 43 placed overthe spindle and screwed on the lower end of said plug 40.

The operation will now be described.

Valve or valve member 18 controls the port 21 in the seat 20 and ismoved up or. down in accordance with the movement of diaphragm 17?Pressure from the thermal unit or chamber 28 prevails at the upper sideof the diaphragm, and condenser. pressure prevails at the lower side ofthe diaphragm. The spring 19 exerts upward pressure on the valve orvalve member *18 and therefore acts on the diaphragm in opposition tothe pressure from the thermal unit. adjustment of the spring pressuremay be effected by means of the screw or adjusting spindle 39.

When the thermal unit pressure equals the condenser pressure, theexpansion valve opens under the influence of the spring 19. When theliquid level in the condenser falls following discharge of liquid to thelow pressure sideof the system, the thermal unit pressure increasesunder the influence of hot gas in the inner tube 11 and overbalancesboth the condenser pressure and the spring pressure, thus closing theexpansion valve. Then the liquid again accumulates in Suitable thecondenser and flowing through the tube the diaphragm to be overbalancedby the" combination of condenser and spring pressures and-the valve tobe opened. Liquid refrigerant lying at a certain level in the jacket 29is caused to boil at the condensing pressure by heat received from thethermal unit. The gas given ofi by this boiling leaves the jacket veryfreely through the pipe 30a and therefore permits such boiling at thesame pressure as prevails in the condenser.

It will be apparent that, in a system equipped with a liquid levelcontrol embodying the present invention, the expansion valve may belocated at any desired level. Furthermore, inasmuch as the line from thecondenser to the expansion valve is a high pressure and high temperatureline and'the valve may be located close to a cooler or the like, thereis no necessity for the considerable amount of heat insulating coveringwhich is required in connection with th usual forms of liquid levelcontrols.

I claim 1. In a refrigerating system, the combination with a condenser,a conduit to with draw condensed liquid refrigerant from saigl condenserand a thermostatic valve controlled. by a diaphragm and controlling suchwithdrawal of liquid refrigerant, of a conduit for supplying refrigerantvapor to said condenser and having a horizontal portion at apredetermined level for the maintenance of liquid level in saidcondenser, a jacket forming thermal chamber surrounding such vaporsupplying conduit and connected with said valve at one side of saiddiaphragm to open said valve upon decrease of pressure in said thermalchamber and to close said valve upon increase in pressure, said acketaround said thermal chamber being connected at its lower part withthe-liquid containing part of the condenser and at its upper part withthe vapor containing part of the condenser.

2. A combination of apparatus of the character described, comprising athermal unit, a condenser, a valve, a diaphragm in said valve, means forexerting a pressure on one side of said diaphragm responsive totemperature changes in said thermal unit, means for applying pressure tothe other side of said diaphragm responsive to changes in condenserpressure within the condenser, a spring withinthe valve, said springbeing arranged to exert a pressure on said diaphragm in combination withsaid pressure from the condenser, in opposition to the pressure exertedupon said diaphragm from the thermal unit.-

3. A combination of apparatus for controlling the level of liquid in acondenser comprising a supply passage for said condenser,a thermal unit,a valve, a first chamber surrounding said supply passage comprising partof said thermal unit and containing a fluid, a diaphragm within thevalve, means for connecting said first chamber to one side of saiddiaphragm, a second chamber surrounding said first chamber and connectedto said condenser, means for connecting said condenser, to exert apressure responsive to changes in condenser pressure on the other sideof said diaphragm, and a spring within the valve for causing said valveto function responsive to changes in said pressure, the functioning ofsaid valve controlling the'level of the liquid with in the condenser.

4. A condenser and means for controlling in the condenser responsive tochanges inpressure within said unit and within the condenser. j

5. In a refrigeratlon system having a condenser,'m'eansforcontrolling'the level of refrigerant withinthe condenser comprising athermal unit, a jacket surrounding said unit and connected to saidcondenser at a plurality of points, a valve, a diaphragm within thevalve, means for admitting liquid from said condenser to exert apressure on one side of said diaphragm, means for charging said unitwith refrigerant at a desired pressure, means for connecting said unitto the other side of the diaphragm, means for varying the pressure insaid unit responsive'to changes in temperature in said jacketsurrounding said unit, said valve being arranged to control the level ofliquid within the condenser whenever the pressure in the thermal unit isat a predetermined variance from the condenser pressure.

6. A container and means for controlling the level of liquid thereincomprising a supply passage for said container, a thermal unitsurrounding said supply passage and parallel to the level of liquid insaid container, a valve, a diaphragm in the valve, means'for admittingliquid from said container to exert a pressure on one side of saidvalve, means for connecting said unit to the other side of said valve, ajacket surrounding said unit, and means for connecting said jacket tosaid container at a point below the desired liquid level and at anotherpoint above the desired liquid level.

HENRY H. MARSHA iL.

